Two Galaxies Masqueraded as One: New Image Unveils Illusion

It turns out that two galaxies have been tricking astronomers for years. What looked like a colossal jet shooting away from a galaxy turned out to be an illusion. New data from the Karl G. Jansky Very Large Array (VLA) revealed that two galaxies, one lying behind the other, have been masquerading as one.

The closer galaxy in this new image, called UGC 10288, is located about 100 million light-years away. It's spiral in shape, but from Earth's viewpoint you can only see its thin edge. The galaxy that's further away is nearly 7 billion light-years away and appears to be blue in the picture. Two giant jets shoot away from this galaxy, one of which is seen above the plane of the closer galaxy's disk.

So how did these two galaxies trick astronomers? Earlier radio images appeared as one fuzzy blob, which made researchers believe they were looking at one galaxy instead of two. As instruments improved, though, so did the image of the galaxies.

"We can use the radio waves from the background galaxy, coming through the nearer one, as a way to measure the properties of the nearer galaxy," said Judith Irwin, one of the researchers, in a news release.

In fact, the scientists spotted new structures in the closer galaxy's disk in these recent images. They spotted an arc-like feature rising more than 11,000 light-years above the disk, as an example. This, in turn, can help researchers learned a little bit more about the galaxies in general.

The findings don't just reveal a little bit more about the galaxies, though. They also show the importance of developing new instruments to more clearly see the universe that we're a part of. As technology improves, we're learning more and more about distant objects in the universe that, although observed before, are now being revealed to be something quite different.

The findings are published in The Astronomical Journal.